1. Field of the Invention
The present invention relates to an endoscopic puncture needle which is inserted into a surgical instrument insertion channel of an endoscope to be used, and a method of acquiring tissue from a target region by using the endoscopic puncture needle.
2. Description of the Related Art
A biopsy puncture needle having a hollow needle member which is used to acquire tissue from a lung of a patient is disclosed in, e.g., a specification of U.S. Pat. No. 4,799,494. The biopsy puncture needle includes a hollow inner needle which is movable along the axial direction of a hollow outer needle. Therefore, the inner needle is made to protrude with respect to the outer needle at a position where it faces tissue, and the tissue is drawn into the inner needle by suction. At this time, a pressure at a distal end of the needle member is monitored by using a balloon.